Kimberly-Clark already has sold more than 2 million packages of the diapers in North America. That’s a significant dent, given that there are less than 9-million estimated toddlers in the Little Movers diaper sizes at any given time in North America.

Kimberly-Clark hit its highest point in the category since December, before rival Procter & Gamble Co. launched its thinner “earth-friendlier” Dry Max diaper line in March.